\(\displaystyle \sqrt{x+2}-x = 0.\)
\(\displaystyle \sqrt{x+2} \ = \ x,\)
\(\displaystyle x+2 \ = \ x^2, \ squaring \ both \ sides.\)
\(\displaystyle x^2-x-2 \ = \ 0.\)
\(\displaystyle (x-2)(x+1) \ = \ 0, \ \implies \ x \ =2 \ or \ x \ = \ -1.\)
\(\displaystyle Check \ in \ original \ equation, \ mandatory: \ x \ = \ -1 \ \implies \ 2 \ = \ 0, \ I \ don't \ think \ so.\)
\(\displaystyle x \ = \ 2, \ 2-2 \ = \ 0, \ checks, \ hence \ only \ solution \ to \ equation \ is \ x \ = \ 2.\)